1. Field of the Invention
The present invention relates to an accumulator. More specifically, the present invention relates to an improved accumulator and a method of assembling the refrigerant accumulator for use in a refrigeration circuit.
2. Description of the Prior Art
In a conventional vapor compression refrigeration circuit a compressor acts on refrigerant to raise its temperature and pressure. This refrigerant then is condensed from a gas to a liquid in a condenser giving off heat. This liquid then undergoes a pressure drop through an expansion device and is conducted to an evaporator where it changes state from a liquid to a gas absorbing heat during the phase change. This gaseous refrigerant is then conducted back to the compressor to complete the cycle.
Under certain operating conditions all of the liquid refrigerant may not be changed from a liquid to a gas in the evaporator. Also if the refrigerant circuit is overcharged there is an excess of refrigerant. Under either of these conditions it is possible for liquid refrigerant to pass from the evaporator to the compressor.
The compressor operates on gaseous material and consequently the entry of any liquid phase refrigerant creates potential for damage to the compressor. The entry of liquid in the form of droplets into the compressor is referred to as "slugging" and may cause crankshaft damage as well as damage to the valves and other internal mechanisms of the compressor.
A suction line accumulator may be mounted between the evaporator and the compressor to separate the liquid components from the gaseous components of the incoming stream of refrigerant fluid. The accumulator acts to temporarily retain the refrigerant in the liquid state so as to prevent liquid refrigerant from being returned to the compressor or at least to greatly reduce the possibility of such an occurrence. The accumulator may also be used to control the relative rate of flow of lubricant mixed with the refrigerant. This lubricant, typically oil, is cycled through the circuit and provides the necessary lubrication for the compressor.
In heat pumps wherein the direction of flow of refrigerant within the refrigeration circuit is reversed such that the evaporator and condenser switch functions, it is often necessary to defrost one of the heat exchangers as well as to provide for the switching between modes of operation. Depending upon the mode of operation and whether or not the unit is in defrost the quantity of refrigerant charge necessary for optimum system operation may vary. Under these conditions the accumulator may be used as a storage location for excess refrigerant within the circuit.
The accumulator described herein has a single tube to which a cylindrical shell has been mounted. Appropriate inlet and discharge openings are created in the tube such that refrigerant from the evaporator may flow into the accumulator and gaseous refrigerant together with lubricant may be discharged from the accumulator to the compressor suction line.